I have a 94 Shadow ES 3.0V6. It's my next project car after I finish with my current one. Some of the things I was considering was swapping heads to the dohc from a stealth and bumping the compression either to the stock stealth 10:1 or going up a notch more and going to 11:1. As well as forged rods, and maybe a little juice.

 

Have fun wiring the Stealth ECU into a shadow. If you can find yourself a how-to on the 'Net somewhere, and are pretty confident with wiring, then I'd say go for it! Otherwise, you may be biting off more than you can chew.

I'd say the High compression route would be your best bet to start off with, but keep in mind that when you bump up the compression, valve clearance becomes an issue. Your non-interferance engine becomes an interferance-type engine, meaning that if your timing belt breaks, valve hits piston and... boom! dead engine!

 

I think I could live with that risk. What I'm really wondering about is the cam profile. Cause cam profile can really mess with effective CR. Don't know if the claimed 8.85 is the CR of the piston/chamber design sans cam effects or is it the effective CR. A long duration cam will drop the effective CR alot.

 

So the key would be to find a cam profile that has a good combination of lift and duration, without affecting the CR too badly...

 

yeppers. cause the longer it stays open on the compression stroke the less effective compression. Some high duration cams the intake won't actually fully close till the crank is 20-30 degrees into the compression stroke. The distance the piston travels in the time is lost compression. Which is lost power.

 

Well, talked to a friend of mine who works in a machine shop that specializes in race engines. He didn't have time to go into the details, but said that it really wasn't a good idea to bump up the compression on a none interference engine. I'm gonna talk to him again later when he can go into details, but since the galant and the 3000/stealth both have the same bottom end and are running 10:1, I'm guessing that the difference is the combustion chamber design of the heads. So if I want to up compression I'm either going to have to see if I can put the galant or 3000/stealth sohc heads on or the dohc heads, although the more I think about the less I really want to try and mate the dohc ecu into the Shadow. Gonna have to see what my friend thinks. did see some sohc Stealth heads for 325.00 a piece on greenleafauto.com

 

When it comes up to compression combined with cam profiles... The compression is the same no matter what the cam profile is, with this in mind.

The more the profile of the cam the longer it stays open, normally the cmopression the engine would build up is lower. but most compression ratings are based on squish bands. The flat spot or band on the top of the piston makes use of this, the larger it is the higher your compression, this also applies to the head. What would be say a 12.1 comp in a stock cammed engine if you used the same piston in a engine, with a high profile it would be considerably less compression.

Another factor with compression is the exhaust profile, if you have the ehaust open sooner and close about the same timeas stock with say a LSA on the exhaust about 3-5 degree advance than you would be able of a bigger intake profile.

the lsa would be wider not closer say a 108 stock 111 mod this meand the seperation would be wider but you need to specify to keep the stock lsa on the intake side, when you install it install normal the, lsa is comsidered altered wich meand you would have a stock lsa intake witha 3 deg. advance exhaust when installed straight up.

The suish profile on the piston usually will determine the compression, the larger the squish band the higher the static compression should be, they call it static because its theoretical. this means that if the you alter the squish clearance (planing the head) or cam profile the static compression will change. there is a formuala in the engine builder book will have to check that cam give you the changes..
Alot of time changing the piston and the cam profile is better than changing or screwing witht ehh head.

 

Well the intake is done, and installed on my mock up motor, i kept a spare engine and tansmission on my garage, obvious reasons.
Actualy it spun a crank bearing when i was relieving my cooling system, so i yanked it out the next day, didn't want to ruin it completely. Other than tinting the metal from welding it looks cool, but in my plans the plenum sits lower than the port mounts. Wondering if the fuel will drop out because of it.
After all each runner is 36" long and 2" diameter pipes. The next step is to bore out the SP TBI while paying attention to the idle, and egr circuits. Havent' worked in the egr pipe yet, that will take some manuevering.
Well the original design called for 52" long runners, try to fit that under the hood..[>:] not to mention the plenum would have to be at least another8-12" long, Tried but ti just wasn't going to work.
right now I'm welding up my special flow muffler that is 1 in 2 out, and it bolst up between the tire carrier and the rear roll pan. don't know how loud it will be but the design looks cool on the car, Especially when you only see Quad tail pipes two on each side.

you want something original you have to do it yourself piece by piece or pay out hte *** to hire engineers to make it.

The problem is that I have no camera and no scanner, so pics will be in due time, face it when you only make $240 - $350 a week investing in a camera and scanner would halt production very quickly.

 

Hey i have another mod idea, its kinda complicated to do but I think I could make it happen Let me run it by you guys, How about a waste gate turbo system one that will not let any exhaust into the turbo until a cerain dialed in rpm range, now have that turbo bolted to a single pioint throttle body, witha modified injector program into the computer that would allow the injector to compinsate for boosted conditions at that and all conditions so that the car would not have to run rich all the time. Also the turbo would be connected similar to the exhaust waste gate as to only when the turbo kicks on the gate closes to allow boost to the engine during deceleration and normal unboosted condition the gate would allow the engine to breathe NA

I have the diagram already drawn and most of the electronics to use. You would have to use a 91 i think or nwer single point, the fuel pressure for those is 37 psi, or better yet use a 2.8l gm 220 tbi two injectors, one firse constant and the other firse off a switch that activates whent he cutout for the NA systems engages.

you may have to make a new intake for the volume of air that would be coming in max cfm Intake size = max turbo cfm flow not boost this way the intake can hold a full charge if you will at all times of what teh motor can take per full firing order.
All you would need is the cfm filling capability of the turbo boost to the cylinder inf cfm, then mix the fuel accordingly to create a perfect 14.7-1 or richer mixture. The most sofistcation that you would need is a program for the injectors(programmiable) and a fuel system that can read boost and increase fuel pressure and volume in a split second, (fuel computer override program..)

 

Trust me shaving the heads works quite well. i got a friend who bought a 1999 chevy cavalier, he shaved the heads ten and straight piped it. he bought it for $400. What can i say he can do one hell of a burnout even though it has the 2.2. Even if it was a reverse drop. BTW he could fix the tranny if something goes wrong. But anyway shaving the heads does do good but just dont overdo it. We all know what happens when you have too much compression.